Fossil fuel resources are finite, and are widely expected to dwindle in the not too distant future. As these resources become more scarce, the costs of extracting fuel will increase, as well as the cost of the resource itself due to increased competition and demand. Such costs are likely to put increased pressure on economies worldwide. Thus, fossil fuel utilization presents potential issues to future energy security and financial interests. Alternative fuel resources should be identified to limit reliance on fossil fuels.
In addition, the total amount of municipal solid waste (MSW) generated in the US alone has increased by three-fold from 80 million to 250 million tons over the past 50 years. In 2008, 12% of this total was non-biodegradable polymers (plastics). Only 7% of these plastic components are recycled, due to limited markets and limited consumer compliance. Solutions are needed to address the issues of (a) continuously decreasing available landfill space, (b) ubiquitous pollution problems (e.g., the Great Pacific Garbage Patch) and, (c) wasting such an energy dense fossil-fuel-derived resource. Accordingly, it is important to eliminate or reduce the amount of waste that ends up in the environment.
One potential way to eliminate organic waste is to incinerate it. Nonetheless, conventional techniques of burning waste organic waste material tend to be harmful to the environment and health of people. Another potential path to eliminating organic waste is to convert it into fuel. Organic waste has a tremendous amount of stored energy. Direct combustion of waste plastics, for instance, in waste incinerators releases their stored energy, which is on the order of 46,000 kJ/kg, and is comparable to those of the premium fuels of gasoline, diesel oil and natural gas. However, such conventional direct combustion techniques lead to uncontrollable, inefficient energy production that also generates large amounts of health-hazardous soot and hydrocarbons. This is demonstrated in FIG. 2, where combustion of a Styrofoam cup (polystyrene) releases soot and toxic fumes.
Therefore, there is a need for systems and methods for extraction of fuel and/or energy from energy-dense solid organic waste materials, such as waste plastic, without releasing dangerous and unhealthy compounds.